The first cleaning of the surface, finished on the back of the sculptural group and in the initial phase on the front, is bringing to light the colors resulting from previous treatments of the marble and unknown details of Michelangelo's Pietà - from the signs of processing made with different tools, to the imprints of the pieces of the nineteenth-century cast - to the traces of previous interventions - hidden under a thick layer of dust deposits mixed with waxes, accumulated and modified in over 470 years of the life of the work.